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(No Model.)

E. S. BOYNTONJ PIPE WRENCH.

No. 404,770. Patented June 4, 1889.

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N. PETERS. PhoKbUthngr-npher. Walhinglnn. 0.0.

UNITED STATES PATENT OFFICE.

EDWVARD S. BOYNTON, OF N EW YORK, N. Y., ASSIGNOR TO THE CAMPBELLPRINTING PRESS AND MANUFACTURING COMPANY, OF SAME PLACE,

PIPE-WRENCH.

SPECIFICATION forming part of Letters Patent N0. 404,770, dated June 4,1889. Application filed Nvember2 6, 1888. Serial No. 291,873. (Nomodel.)

To aZZ whom it may concern:

Be itknown that I, EDWARD S. BoYNToN, of the city of New York,in thecounty and State of New York, have invented a new and useful Improvementin Alligator Wrenches,

which invention is fully set forth and illustrated in the followingspecification and accompanying drawing.

The object of this invention is to provide [0 an adjustable pipe-wrenchoperating upon the alligator principle, which shall avoid the tendencyin such wrenches to crush the pipe under great resistance to rotation.

The invention will first be described in de- I5 tail and thenparticularly set forth in the claim.

In the solid alligator-wrench, and such an adjustable form of it as isshown in PatentNo.

364,749, issued to me June 14, 1887, one of the jaws is preferablywithout serrations or teeth,

for the purpose of insuring a secure hold being taken on the pipe or rodby the toothed jaw through the stiding of the pipe upon the smooth jawup into the angle formed by the two. Under severe strains, however, itis found in practice that in thus forcing the pipe into the wedge-shapedopening of the jaws there is considerable tendency to flatten or crushthe pipe operated upon. To avoid this 0 tendency, the smooth oruntoothed jaw in this invention is formed with one or more steps in itof such form that, under a given adjustment of opening, the pipe mayslide upon the smooth jaw until the toothed jaw has taken a firm holdand further entrance of the pipe 3 5 into the opening of the wrench beprevented by contact with one of the steps formed in the smooth jaw.

In the accompanying drawing is shown in side elevation such a wrench,for the specific construction of which reference is had to the patent,No. 364,749, above mentioned.

In said drawing, 1 indicates the stationary jaw, in which are formedsteps, as at 2 and 3. 4 indicates the movable serrated jaw; 5, thewashers; 6, the rivet, and 7 the screw upon which the ad justing-nut 8works. The dotted circles resting on the steps formed in the smooth jawat 2 and 3 show the operation of the jaws upon different sizes of pipe.

Having thus fully described my said improvement as of my invention, Iclaim-- In an adjustable wrench operating to rotate pipes or rods bymeans of a wedgeshaped opening on what is known as the alligatorprinciple, the combination of a toothed or serrated jaw on one side ofthe angular opening, and a smooth jaw on the other side containing oneor more steps or stops, as 2 3, whereby the opening between the jaws may60 be so adjusted that a firm hold is taken by the toothed jaw andflattening or crushing of the pipe or rod avoided, substantially as setforth.

EDWARD S. BOYNTON.

Witnesses:

JOHN TULLY, FRANK L. ENTwIsLE.

